Titius-Bode Law

A prescription for calculating planetary distances, made famous by Johann
Bode but first pointed out in 1766 by the German
mathematician Johann Titius (1729–1796). It is that the distance to
the nth planet is 0.4 + (0.3)n astronomical units
AU. The Titius-Bode Law, also known simple as
Bode's Law works surprisingly well out to Uranus
but then breaks down.